The Nativity scene and tree will remain in St Peter's Square until the feast of the Lord's Baptism on 9 January

Baby Jesus, whose parents could find no decent shelter and had to flee persecution, is a reminder of the "painful experience" of so many migrants today, Pope Francis said, just before the Vatican Christmas tree was lit and its Nativity scene unveiled for the first time last Friday.

Nativity scenes all over the world "are an invitation to make room in our life and society for God - hidden in the gaze of so many people" who are living in need, poverty or suffering, he told people involved in donating the tree and creche for St Peter's Square.

The northern Italian province of Trent donated the 82-foot-tall spruce fir, which was adorned with ceramic ornaments handmade by children receiving medical treatment at several Italian hospitals.

The 55-foot-wide Nativity scene was donated by the government and Archdiocese of Malta. It features 17 figures dressed in traditional Maltese attire, as well as a replica of a Maltese boat to represent the seafaring traditions of the island.

The boat also symbolises "the sad and tragic reality of migrants on boats headed toward Italy," the Pope said in his speech in the Vatican's Paul VI hall. "In the painful experience of these brothers and sisters, we revisit that [experience] of baby Jesus, who at the time of his birth did not find accommodation and was born in a grotto in Bethlehem and then was brought to Egypt to escape Herod's threat."

"Those who visit this creche will be invited to rediscover its symbolic value, which is a message of fraternity, sharing, welcoming and solidarity," the Pope said.

The beauty of the pristine forests of northern Italy where the tree grew "is an invitation to contemplate the creator and to respect nature," he said, adding that "we are all called to approach creation with contemplative awe".

The Nativity scene and tree will remain in St Peter's Square until the feast of the Lord's Baptism on 9 January.

Archbishop Lauro Tisi of Trent, speaking at the tree-lighting ceremony as the sun set, told people in St Peter's Square that the towering tree had been growing for decades; decades that have seen thousands of people from the region emigrate in search of work. It's unconscionable, he said, that people today refuse to welcome those coming from poorer places with the same needs and dreams.

Between the life-size Nativity scene and the Christmas tree, the Vatican placed a cross and chunks of the facade of the Basilica of St Benedict in Norcia, Italy. The basilica was destroyed by an earthquake in October and dozens of other churches in central Italy crumbled or were heavily damaged. Money left at the Nativity scene by visitors will be donated to the church rebuilding effort in Norcia.